Circuit carrier and manifacturing method thereof

ABSTRACT

A circuit carrier and a manufacturing method thereof are provided. The circuit carrier for coupling an electronic device includes a flexible structure and a circuit structure. The flexible structure includes a conductive pattern disposed on a surface of a first dielectric layer. The circuit structure includes a second dielectric layer overlying the surface of the first dielectric layer and a circuit layer disposed on the second dielectric layer and connected to the conductive pattern. The flexible structure is embedded in and electrically connected to the circuit structure, and a portion of the flexible structure extends out from an edge of the circuit structure to be plugged into the electronic device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of and claims thepriority benefit of a prior application Ser. No. 16/218,489, filed onDec. 13, 2018, now pending. The prior application Ser. No. 16/218,489claims the priority benefit of U.S. provisional application Ser. No.62/752,362, filed on Oct. 30, 2018. The entirety of each of theabove-mentioned patent applications is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND

Generally, contemporary high performance computing systems consisting ofone or more electronic devices have become widely used in a variety ofadvanced electronic applications. In terms of the packaging used forintegrated circuit components or semiconductor chips, one or more chippackages are generally bonded to a circuit carrier (e.g., a systemboard, a printed circuit board, or the like) for electrical connectionsto other external devices or electronic components.

Overall electrical performance of electronic systems is affected by eachof the key components, including the performance or structure of memorydevices, processing devices, input/output (I/O) devices, any associatedinterface elements, and the type and structure of interconnectinterfaces. Existing connectors in circuit carriers have faced seriouscontact resistance issues due to multi-interfaces degradation. As demandfor miniaturization, higher speed and better electrical performance(e.g., lower transmission loss and insertion loss) has grown recently,there has grown a need for more creative packaging and assemblingtechniques.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIGS. 1A through 5B are various views showing various stages in amanufacturing method of a flexible structure, in accordance with someembodiments.

FIGS. 6 through 15 are schematic cross-sectional views showing variousstages in a manufacturing method of a circuit carrier, in accordancewith some embodiments.

FIG. 16 is a schematic cross-sectional view showing a circuit carrier,in accordance with some embodiments.

FIGS. 17 and 18 are schematic plan views showing different types ofcircuit carriers, in accordance with some embodiments.

FIG. 19 is a schematic view showing an application of a circuit carrier,in accordance with some embodiments.

FIG. 20 is a schematic cross-sectional view showing an electronicassembly, in accordance with some embodiments.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Other features and processes may also be included. For example, testingstructures may be included to aid in the verification testing of the 3Dpackaging or 3DIC devices. The testing structures may include, forexample, test pads formed in a redistribution layer or on a substratethat allows the testing of the 3D packaging or 3DIC, the use of probesand/or probe cards, and the like. The verification testing may beperformed on intermediate structures as well as the final structure.Additionally, the structures and methods disclosed herein may be used inconjunction with testing methodologies that incorporate intermediateverification of known good dies to increase the yield and decreasecosts.

FIGS. 1A through 5B are various views showing various stages in amanufacturing method of a flexible structure, in accordance with someembodiments, where FIG. 1A is a schematic perspective view showing acomposite structure 1000, FIG. 1B is a schematic cross-sectional view ofFIG. 1A, FIGS. 2A, 3A, 4A, and 5A are perspective views illustrating theintermediate steps during a process for forming a flexible structure100, and FIGS. 2B, 3B, 4B, and 5B are schematic cross-sectional viewstaken along the A-A line in FIG. 2A and illustrating intermediate stepsduring the corresponding process.

Referring to FIG. 1A and FIG. 1B, a composite structure 1000 isprovided. For example, the composite structure 1000 includes adielectric layer 1100 and at least one conductive layer 1220, 1240formed thereon. The dielectric layer 1100 may include polymericmaterials (e.g., polyimide (PI), benzocyclobutene (BCB), polybenzoxazole(PBO), or the like) or other suitable electrically insulating materials.In some embodiments, the dielectric layer 1100 is a resin film (e.g., athermosetting film, a thermoplastic film) or a laminate of such flexiblefilms. The dielectric layer 1100 may be a single film or a multi-layeredfilm, which is not limited in the disclosure. In some embodiments, thecharacteristics of the dielectric layer 1100 include heat resistance,flexibility, electrical properties, and so on. The thickness thedielectric layer 1100 can be optimized for different applications, whichis not limited in the disclosure. In some embodiments, the conductivelayers 1220 and 1240 are formed directly on the dielectric layer 1100,and the conductive layers 1220 and 1240 are in direct contact and inphysical contact with two opposite surfaces (e.g., a first surface 1100a and a second surface 1100 b) of the dielectric layer 1100. Theconductive layers 1220 and 1240 may be made of the same or similarconductive materials, such as copper, gold, silver, aluminum, zinc, tin,lead, combinations thereof, alloys thereof, or the like. For example, aconductive material is deposited on the first surface 1100 a and thesecond surface 1100 b of the dielectric layer 1100 using any suitablemethod (e.g., laminating, sputtering, plating, or the like) torespectively form the conductive layers 1220 and 1240. It should beappreciated that the conductive layers formed over double sides of thedielectric layer shown in the drawing merely serve as an exemplaryillustration; however, the conductive layer may be formed on a singleside of the dielectric layer depending on the design requirements.

Referring to FIG. 2A and FIG. 2B, a flexible structure 100 is formed.For example, the conductive layers 1220 and 1240 of the compositestructure 1000 are patterned to form conductive patterns 122 and 124respectively. In some embodiments, at least portions of each of theconductive layers 1220 and 1240 are removed using lithography andetching processes or any suitable patterning technique to definepatterns correspondingly on the first surface 1100 a and the secondsurface 1100 b of the dielectric layer 1100. For example, thelithography process may include forming a photoresist pattern (notshown) over the dielectric layer 1100 with openings whichcorrespondingly expose the predetermined regions of each of theconductive layers 1220 and 1240. Subsequently, the subtractive etchingprocess, which may be conducted as a single etching step or multiplesteps, may be performed to remove the uncovered conductive layers 1220and 1240 and to form the conductive patterns 122 and 124. Afterpatterning the conductive layers 1220 and 1240, at least a portion ofthe first surface 1100 a and at least a portion of the second surface1100 b are respectively exposed by the conductive patterns 122 and 124.

In some embodiments, at least one of the conductive patterns 122 and 124includes a terminal-connecting portion Ct (i.e. a peripheral portion ofthe conductive pattern), a trace line portion Lt connected to theterminal-connecting portion Ct, and a via-connecting portion Cvconnected to the trace line portion Lt. The terminal-connecting portionCt of the conductive pattern 122 and/or 124 may be distributed at theperiphery of the dielectric layer 1100. In some embodiments, theconductive patterns 122 and 124 are symmetric with respect to thedielectric layer 1100. In alternative embodiments, the conductivepattern 122 has an asymmetrical configuration with respect to theconductive pattern 124. After formation, the flexible structure 100 maybe freely foldable, thereby providing a high mounting flexibility.

Referring to FIGS. 3A, 3B and FIGS. 4A, 4B, in some embodiments, theflexible structure 100 further includes coverlay materials 1320 and 1340respectively covering the conductive patterns 122 and 124. For example,the coverlay materials 1320 and 1340 may be formed over the first andsecond surfaces 1100 a and 1100 b of the dielectric layer 1100 torespectively cover the conductive patterns 122 and 124. For example, thecoverlay materials 1320 and 1340 may be formed by deposition,lamination, spin-coating, or any suitable technique. In someembodiments, the coverlay materials 1320 and 1340 may be organic films,inorganic films, composite layers (e.g., including a polymer adhesivelayer coated on a dielectric film), or other suitable insulatingmaterials. After forming the coverlay materials 1320 and 1340, at leastthe terminal-connecting portions Ct of the conductive patterns 122 and124 are exposed by the coverlay materials 1320 and 1340 for furtherelectrical connection. The coverlay materials 1320 and 1340 mayrespectively cover the via-connecting portions Cv of the conductivepatterns 122 and 124. In some embodiments, the coverlay materials 1320and 1340 partially cover the trace line portions Lt of the conductivepatterns 122 and 124. For example, parts of the trace line portions Ltimmediately connected to the terminal-connecting portions Ct may beexposed by the coverlay materials 1320 and 1340. In some embodiments,the periphery of the dielectric layer 1100 may be exposed by thecoverlay materials 1320 and 1340. For example, the coverlay material1320 (or 1340) may expose at least two opposite margins of the firstsurface 1100 a (or second surface 1100 b) of the dielectric layer 1100.

Referring to FIG. 5A and FIG. 5B, in some embodiments, the flexiblestructure 100 further includes surface finish layer(s) 142/144 at leastformed on the terminal-connecting portions Ct of the conductivepattern(s) 122/124, respectively. In some embodiments, the surfacefinish layer(s) 142/144 fully covers the exposed terminal-connectingportions Ct (e.g., including covering the sidewalls and the exposed top(bottom) surfaces of the terminal-connecting portions Ct). The surfacefinish layers 142 and 144 may include different materials as one or morelayers, and may be used to prevent oxidation and/or improveconductivity. A material of the surface finish layers 142 and 144 mayinclude nickel, gold, palladium, Electroless Nickel Immersion Gold(ENIG), Electroless Nickel Electroless Palladium (ENEP), ElectrolessNickel Electroless Palladium Immersion Gold (ENEPIG), and/or the like.The formation of surface finish layers 142 and 144 may includeimmersion, plating, or the like. In some embodiments, the surface finishlayers 142 and 144 and the underlying terminal-connecting portions Ct ofthe conductive patterns 122 and 124 are viewed as a connector forfurther electrical connection.

FIGS. 6 through 15 are schematic cross-sectional views showing variousstages in a manufacturing method of a circuit carrier C1, in accordancewith some embodiments. Referring to FIG. 6 and FIG. 7, a firstpre-patterned dielectric layer (e.g., layers 2120, 2140) and aconductive material (e.g., layers 2220, 2240) are provided over one sideof the flexible structure 100. For example, the first pre-patterneddielectric layers 2120 and 2140 are respectively formed over the twoopposite sides of the flexible structure 100 by deposition, lamination,spin-coating, or any other suitable technique. In some embodiments, thefirst pre-patterned dielectric layers 2120 and 2140 are respectivelyformed over the coverlay materials 1320 and 1340. In some embodiments,the first pre-patterned dielectric layers 2120 and 2140 may have gooddepositing adhesion applied thereon. For example, the firstpre-patterned dielectric layer 2120/2140 includes a prepreg sheet, apolymer layer (e.g., Ajinomoto build-up film (ABF), a polyimide film,any other suitable laminate film), and/or the like. In some embodiments,the material of the first pre-patterned dielectric layer 2120/2140 isstiffer than that of the dielectric layer 1100 of the flexible structure100. For example, the Young's modulus of the first pre-patterneddielectric layer 2120/2140 is different from that of the dielectriclayer 1100 of the flexible structure 100. In some embodiments, theYoung's modulus of the first pre-patterned dielectric layer 2120/2140 isgreater than the Young's modulus of the dielectric layer 1100 of theflexible structure 100. The Young's modulus of the first pre-patterneddielectric layer 2120/2140 may range from about 10 GPa to about 35 GPa.The Young's modulus of the dielectric layer 1100 of the flexiblestructure 100 may be in a range from 2 GPa to 10 GPa approximately.

In some embodiments, a dielectric material is patterned to form thefirst pre-patterned dielectric layer (e.g., layer 2120/2140) includingat least one opening OP1, which may expose a peripheral region 100P ofthe flexible structure 100. In some embodiments, each of the firstpre-patterned dielectric layers 2120 and 2140 includes a circuitryregion CR and a non-circuitry region NCR connected to the circuitryregion CR. For example, the openings OP1 are provided within thenon-circuitry region NCR. The non-circuitry region NCR may overlap theperipheral region 100P of the flexible structure 100. In someembodiments, the location of the non-circuitry region NCR coincides withthe location of the peripheral region 100P, while the span of thenon-circuitry region NCR extends beyond the span of the peripheralregion 100P. In some embodiments, the openings OP1 are pre-patterned(e.g., using a punching process or the like) in a suitable dielectricmaterial prior to the disposition on the flexible structure 100. Othermethods for patterning dielectric material to form the firstpre-patterned dielectric layer (either before or after being disposed onthe flexible structure 100) may also be employed. As referred to herein,the opening OP1 is not intended to be limited to any particular number,shape, and size. For example, the opening OP1 of the first pre-patterneddielectric layer 2120 (or 2140) can be sized to expose at least thesurface finish layer 142 (or 144) of the flexible structure 100 forfurther electrical connection.

In some embodiments, the opening OP1 of the first pre-patterneddielectric layer 2120 (or 2140) exposes the surface finish layer 142 (or144) and a portion of the coverlay material 1320 (or 1340) immediatelyadjacent to the proximal end of the surface finish layer 142 (or 144).The exposed portion of the coverlay material 1320 (or 1340) may be sizedaccording to the design requirements. In some embodiments, the firstpre-patterned dielectric layer 2120 may be thicker enough to cover aportion of the lateral surface 1320LS of the coverlay material 1320and/or at least one lateral surface 122LS of the conductive pattern 122and/or at least a portion of the first surface 1100 a of the dielectriclayer 1100. The opening OP1 of the first pre-patterned dielectric layer2120 may expose the rest portion of the lateral surface 1320LS of thecoverlay material 1320. Similarly, the first pre-patterned dielectriclayer 2140 may cover a portion of the lateral surface 1340LS of thecoverlay material 1340 and/or at least one lateral surface 124LS of theconductive pattern 124 and/or at least a portion of the second surface1100 b of the dielectric layer 1100. The opening OPT of the firstpre-patterned dielectric layer 2140 may expose the rest portion of thelateral surface 1340LS of the coverlay material 1340.

In some embodiments, the conductive material (e.g., 2220, 2240) islaminated on two opposing surfaces of the first pre-patterned dielectriclayer 2120/2140 to sandwich the flexible structure 100 therein. Theconductive materials 2220 and 2240 may be respectively formed over thefirst pre-patterned dielectric layers 2120 and 2140 to cover thecircuitry region CR and the non-circuitry region NCR. In someembodiments, the first pre-patterned dielectric layer 2120 (or 2140) andthe overlying conductive material 2220 (or 2240) are formed over theflexible structure 100 during the same process. In some embodiments, theconductive materials 2220 and 2240 are metal foils and may be laminatedon the first pre-patterned dielectric layers 2120 and 2140,respectively. In alternative embodiments, the conductive materials 2220and 2240 are respectively deposited over the first pre-patterneddielectric layers 2120 and 2140 using any suitable technique (e.g.,chemical vapor deposition (CVD), sputtering, printing, plating, or thelike). Examples of conductive materials 2220 and 2240 are copper,tungsten, aluminum, silver, gold, a combination thereof, and/or thelike. In some embodiments, after forming the conductive materials 2220and 2240, the conductive materials 2220 and 2240 respectively cover theopenings OP1 in the non-circuitry regions NCR of the first pre-patterneddielectric layers 2120 and 2140. At this stage, the surface finishlayers 142 and 144 of the flexible structure 100 may be shielded by theconductive materials 2220 and 2240. In some embodiments, the portions ofthe conductive materials 2220 and 2240 covering the openings OPT may bespatially apart from the flexible structure 100. That is, a confinedspace is formed and enclosed by the conductive material 2220 (or 2240),the first pre-patterned dielectric layer 2120 (or 2140), and theflexible structure 100.

Referring to FIG. 8, a first patterned conductive layer(s) 222/224 maybe formed on the first pre-patterned dielectric layer(s) 2120/2140 toelectrically connect the conductive pattern(s) 122/124. In someembodiments, formations of the first patterned conductive layer(s)222/224 may be based on an additive process or a semi-additive process,depending on the manufacturing process. For example, first via hole(s)VH1 at the predetermined position(s) (e.g., corresponding to thecircuitry region CR) are formed by removing portions of the conductivematerial 2220 (or 2240), the underlying first pre-patterned dielectriclayer 2120 (or 2140), the underlying coverlay material 1320 (or 1340)through laser drilling, etching, a combination thereof, or othersuitable removal techniques. After removing portions of the coverlaymaterial 1320 (or 1340), a coverlay layer 132 (or 134) is formed.

In some embodiments, the first via holes VH1 may expose thevia-connecting portions Cv (shown in FIG. 2A) of the conductivepattern(s) 122/124. Next, an additional conductive material (not shown)may be formed inside the first via holes VH1 so as to form firstconductive via(s) VH1 In some embodiments, the first via holes VH1 aresubstantially filled up by the additional conductive material. Theadditional conductive material may also be formed over the remainingportions of the conductive material(s) 2220/2240, thus increasing thethicknesses of the remaining portions of the conductive material(s)2220/2240. In some embodiments, the additional conductive material isformed by, for example, plating, sputtering, or other suitabledeposition techniques. For example, the first conductive vias V1 are inphysical and electrical contact with the conductive pattern(s) 122/124such as the via-connecting portions Cv. In some embodiments, thecoverlay layer 132 (or 134) laterally encapsulates each of the bottomportions of the first conductive vias V1. Each of the top portions ofthe first conductive vias VH1 may be laterally encapsulated by the firstpre-patterned dielectric layer 2120 (or 2140). Next, the remainingconductive material(s) 2220/2240 and the overlying additional conductivematerials are patterned using, for example, lithography and etchingprocess or other suitable processes, thereby providing the firstpatterned conductive layer(s) 222/224.

After formation, those first conductive vias V1 at the same side withthe first surface 1100 a are in electrical and physical contact with theconductive pattern 122 and the first patterned conductive layer 222.Similarly, those first conductive vias V1 at the same side with thesecond surface 1100 b are in electrical and physical contact with theconductive pattern 124 and the first patterned conductive layer 224. Insome other embodiments, the conductive material(s) 2220/2240 may besubjected to a subtractive process so as to form the patternedconductive layer(s) 222/224. Other circuit formation methods may be usedto form the first patterned conductive layer(s) 222/224.

Referring to FIG. 9, a second pre-patterned dielectric layer(s) 2160a/2180 a (along with 2160 b/2180 b in some embodiments) may beoptionally formed over the first pre-patterned dielectric layer(s)2120/2140. In some embodiments, second patterned conductive layer(s) 226a/228 a may be formed over the second pre-patterned dielectric layer(s)2160 a/2160 b/2180 a/2180 b to be electrically connected to the firstpatterned conductive layer(s) 222/224. For example, the secondpre-patterned dielectric layers 2160 a and 2180 a and the overlyingconductive materials are respectively laminated onto the firstpre-patterned dielectric layers 2120 and 2140 (or use other suitabledeposition process) to correspondingly cover the first patternedconductive layers 222 and 224. In some embodiments, the secondpre-patterned dielectric layer(s) 2160 a/2180 a may be provided with theopening(s) OP2 in the non-circuitry regions NCR. For example, theopening(s) OP2 may be substantially aligned with the opening(s) OP1 ofthe first pre-patterned dielectric layer(s) 2120/2140. In someembodiments, the opening(s) OP2 in the non-circuitry regions NCR of thesecond pre-patterned dielectric layer 2160 a (or 2180 a) may be shieldedby the conductive material(s) formed on the second pre-patterneddielectric layer 2160 a (or 2180 a). Those portions of conductivematerials covering the opening(s) OP2 of the second pre-patterneddielectric layer(s) 2160 a/2160 b/2180 a/2180 b in the non-circuitryregions NCR may be spatially apart from the underlying portion of theconductive material shielding the opening(s) OP1 of the firstpre-patterned dielectric layer(s) 2120/2140. In some embodiments, amulti-layered space is formed corresponding to the non-circuitry regionNCR and each layer of the space is separated by these layers of theconductive materials.

Next, the second via hole(s) VH2 may be formed in the secondpre-patterned dielectric layer 2160 a (or 2180 a) and the overlyingconductive material(s) corresponding to the circuitry region CR so as toreach the underlying first patterned conductive layer 222 (or 224) atthe predetermined position(s). Subsequently, additional conductivematerial(s) may be formed and patterned on the remaining portions of theconductive materials in the similar manner as described above so as toform the second patterned conductive layer(s) 226 a/228 a. In some otherembodiments, the second pre-patterned dielectric layer(s) 2160 a/2180 amay be provided with the opening(s) OP2 in the non-circuitry region NCRand the second via hole(s) VH2 in the circuitry region CR, and afterlaminating the second pre-patterned dielectric layer(s) 2160 a/2180 a,conductive material(s) may be deposited inside the second via hole(s)VH2 and extend onto the surface of the second pre-patterned dielectriclayer(s) 2160 a/2180 a to respectively form the second conductive via(s)V2 and the second patterned conductive layer(s) 226 a/228 a.

In some embodiments, the first patterned conductive layers 222 and 224(and/or the second patterned conductive layers 226 a and 228 a) aresymmetric with respect to the dielectric layer 1100. In alternativeembodiments, the first patterned conductive layer 222 (and/or the secondpatterned conductive layer 226 a) has an asymmetrical configuration withrespect to the first patterned conductive layer 224 (and/or the secondpatterned conductive layer 228 a). In some embodiments, theabovementioned steps may be performed multiple times (e.g., formation ofprepatterned dielectric layers 2160 b/2180 b) to obtain a multi-layeredcircuit structure as required by the circuit design. Afterwards, aconductive material(s) 2260 b/2280 b may be formed over the outermostsecond pre-patterned dielectric layer(s) 2160 b/2180 b to be in physicalcontact with the second conductive vias V2 as shown in FIG. 9.

Referring to FIG. 10 and FIG. 11, a sacrificial mask layer(s) PRincluding aperture(s) AP1 may be formed over the conductive material(s)2260 b/2280 b. For example, the apertures AP1 of the sacrificial masklayers PR may correspond to the circuitry region CR. In someembodiments, the apertures AP1 expose at least a portion of theunderlying conductive material(s) 2260 b/2280 b at the predeterminedpositions. In some embodiments, the sacrificial mask layers PR coverthose portions of conductive material(s) 2260 b/2280 b shielding theopening(s) OP2 in the non-circuitry region NCR. The sacrificial masklayer PR may include photoresist material, dry film polymer dielectrics,other sacrificial film materials, or any suitable dielectric material.Next, sacrificial conductive pattern(s) TL may be formed in theapertures AP1 of the sacrificial mask layers PR to be in direct contactwith the underlying conductive material(s) 2260 b/2280 b. A material ofthe sacrificial conductive pattern TL may be different from that of theunderlying conductive material 2260 b, 2280 b. The sacrificialconductive pattern TL may be made of tin, tin-lead alloy, or othersuitable conductive materials. In some embodiments, the sacrificialconductive pattern TL may serve as an etch resist in the subsequentetching step. The sacrificial mask layer PR and the sacrificialconductive pattern TL may be considered sacrificial in the sense thatthey may be ultimately removed, according to some embodiments.

Referring to FIGS. 11, 12 and 13, after forming the sacrificialconductive pattern TL, the sacrificial mask layer PR may be removed toexpose portions of the underlying conductive material(s) 2260 b/2280 bunmasked by the sacrificial conductive pattern TL. For example, thesacrificial mask layer PR may be stripped away using suitable strippingsolutions tailored for particular photoresists. In some otherembodiments, the sacrificial mask layer PR may be dissolved in suitablesolvent or etched using wet chemistry with an appropriate chemicalsolution, plasma etching, and/or the like. In some embodiments, afterremoving the sacrificial mask layer PR, the exposed portions of theconductive materials 2260 b and 2280 b (e.g., unmasked by thesacrificial conductive patterns TL) corresponding to both of thecircuitry region CR and the non-circuitry region NCR are removed by,such as etching or other suitable selective removal techniques, toexpose the outermost second pre-patterned dielectric layers 2160 b and2180 b and to expose the peripheral region 100P of the flexiblestructure 100 (layers 132/134 and 142/144).

In certain embodiments in which the sacrificial mask layers PR areformed on the portions of the conductive materials 2260 b and 2280 b(e.g., shielding the openings OP2), those portions of the conductivematerials 2260 b and 2280 b corresponding to the non-circuitry regionNCR, the underlying portions of the second patterned conductive layers226 a and 228 a (e.g., shielding the openings OP2), and the underlyingportions of the first patterned conductive layers 222 and 224 (e.g.,shielding the openings UPI) are removed during the same removal processsuch that an edge EG of the circuit stack is formed. For example, edgesof the first pre-patterned dielectric layers 2120, 2140, the overlyingfirst patterned conductive layers 222, 224, the overlying secondpre-patterned dielectric layer(s) 2160 a/2160 b/2180 a/2180 b, and theoverlying second patterned conductive layer(s) 226 a/226 b/228 a/228 bmay be substantially aligned. Subsequently, as shown in FIG. 13, thesacrificial conductive pattern TL may be removed using, such asstripping, etching, or other suitable selective removal process, to formthe outermost second patterned conductive layer(s) 226 b/228 b.

Referring to FIG. 14 and FIG. 15, patterned mask layer(s) 230 may beformed over the outermost second pre-patterned dielectric layer(s) 2160b/2180 b corresponding to the circuitry region CR such that a circuitstructure 200 with the flexible structure 100 sandwiched therein isformed. It should be appreciated that the circuit structure 200 formedover double sides of the flexible structure shown in the drawings merelyserves as an exemplary illustration; however, the circuit structure 200may be formed on a single side of the flexible structure depending onthe design requirements.

In some embodiments, the patterned mask layer 230 may protect theunderlying circuitry. For example, the patterned mask layer 230 includesaperture(s) AP2 exposing at least a portion of the outermost secondpatterned conductive layer(s) 226 b/228 b. The patterned mask layer 230may be made of polymeric materials, or other suitable insulatingmaterials. In some embodiments, the patterned mask layer 230 may beformed of materials having a chemical composition of silica, bariumsulfate and epoxy resin, and/or the like. For example, the material ofthe patterned mask layer 230 serving as a solder mask may be selected towithstand the temperatures of molten conductive materials (e.g.,solders, metals, and/or metal alloys) to be subsequently disposed withinaperture(s) AP2.

In some embodiments, a redundant stack RS (e.g., the dielectric layer1100 of the flexible structure 100, the overlying first pre-patterneddielectric layers 2120, 2140, the overlying first patterned conductivelayer 222, 224, the overlying second pre-patterned dielectric layers2160 a, 2160 b, 2180 a, 2180 b, and the overlying second patternedconductive layers 226 a, 226 b, 228 a, 228 b) at the peripherycorresponding to the non-circuitry region NCR may be cut off along ascribed line SL so as to form a circuit carrier C1 as shown in FIG. 15.That is, the structures formed corresponding to the circuitry region CRare remained on the flexible structure 100.

The circuit carrier C1 may be configured to connect an electronic deviceas will be described later herein. In some embodiments, the thickness T1of the circuit carrier C1 ranges from about 50 μm to about 8000 μm. Asshown in FIG. 15, the circuit carrier C1 includes the circuit structure200 and the flexible structure 100 interposed in the circuit structure200, thereby improving folding endurance and flexural properties whilemaintaining rigidity and reliability of the circuit carrier C1. Aportion 100P (as shown in FIG. 12; including the terminal-connectingportion Ct) of the flexible structure 100 is configured to extend outfrom an edge EG of the circuit structure 200 so as to be in contact witha subsequently mounted electronic device.

For example, the flexible structure 100 includes a first dielectriclayer 110 (e.g., the remaining dielectric layer 1100), the conductivepattern(s) 122/124 disposed on the first dielectric layer 110. Thethickness T2 of the flexible structure 100 may range from about 25 μm toabout 300 μm. In some embodiments, the thickness 13 of the firstdielectric layer 110 may range from about 5 μm to about 50 μm. In someembodiment, the thickness T4 of the conductive pattern(s) 122/124 rangesfrom about 5 μm to about 30 μm. The circuit structure 200 electricallyconnected to the conductive pattern(s) 122/124 may include a seconddielectric layer 210 and a circuit layer 220. The circuit layer 220 maybe disposed on and extending into the second dielectric layer 210 so asto be in physical and electrical contact with the conductive pattern(s)122/124. The material of the second dielectric layer 210 may bedifferent from that of the first dielectric layer 110 of the flexiblestructure 100. For example, the Young's modulus of the second dielectriclayer 210 is greater than that of the first dielectric layer 110 so thatthe second dielectric layer 210 may provide a mechanical rigidity of thecircuit carrier C1 and the first dielectric layer 110 may provide amounting flexibility of the circuit carrier C1.

For example, a plurality of sublayers including the remaining firstpre-patterned dielectric layer(s) 212/214 and the remaining secondpre-patterned dielectric layer(s) 216 a/216 b/218 a/218 b may becollectively viewed as the second dielectric layer 210. In someembodiments, the thickness of one of the sublayer of the seconddielectric layer 210 may range from about 5 μm to about 100 μm. Forexample, the sublayer(s) of the remaining first patterned conductivelayer(s) 222′/224′, the remaining second patterned conductive layer(s)226 a′/226 b′/228 a′/228 b′, the first conductive via(s) V1, and thesecond conductive via(s) V2 may be collectively viewed as the circuitlayer 220. In some embodiments, the thickness of one of the sublayer ofthe circuit layer 220 may range from about 5 μm to about 100 μm.

In some embodiments, the flexible structure 100 includes coverlaylayer(s) 132/134 disposed between the conductive pattern(s) 122/124 andthe second dielectric layer 210 of the circuit structure 200, where atleast a portion of the circuit layer 220 (e.g., first conductive viasV1) penetrates through the coverlay layer(s) 132/134 to be in contactwith the conductive pattern(s) 122/124. In some embodiments, thethickness T5 of the coverlay layer(s) 132/134 ranges from about 5 μm toabout 50 μm. For example, the second dielectric layer 210 of the circuitstructure 200 covers a portion of the lateral surface(s) 132LS/134LS ofthe coverlay layer(s) 132/134 and a portion of the top surface(s)132TS/134TS which is connected to the lateral surface(s) 132LS/134LS ofthe coverlay layer(s) 132/134. The second dielectric layer 210 of thecircuit structure 200 may expose the other portion of the lateralsurface(s) 132LS/134LS of the coverlay layer(s) 132/134 and the otherportion of the top surface(s) 132TS/134TS of the coverlay layer(s)132/134. In some embodiments, the second dielectric layer 210 of thecircuit structure 200 is in physical contact with a surface (e.g., firstsurface 110 a, second surface 110 b) of the first dielectric layer 110where the conductive pattern(s) 122/124 is formed thereon, as can beseen in FIG. 15 around the left side edge of the circuit structure 200.In some embodiments, the flexible structure 100 includes the surfacefinish layer(s) 142/144 disposed on the portion (e.g.,terminal-connecting portion Ct) of the conductive pattern(s) 122/124 ofthe flexible structure 100 extended out from the edge EG of the circuitstructure 200. In some embodiments, the circuit carrier C1 includes apatterned mask layer 230 disposed on the circuit layer 220 (e.g., theremaining outermost second patterned conductive layers 226 b′, 228 b′)and exposing at least a portion of the circuit layer 220.

FIG. 16 is a schematic cross-sectional view showing a circuit carrierC2, in accordance with some embodiments. Referring to FIG. 16, thecircuit carrier C2 includes the circuit structure 200A, more than oneflexible structure (e.g., 100A, 100B) interposed inside the circuitstructure 200A, and at least one conductive through hole TH penetratingthrough the flexible structures 100A and 100B so as to be in physicaland electrical contact with the circuit structure 200A. Each of theflexible structures 100A and 100B may be similar to the flexiblestructure 100 described above. The flexible structures 100A and 100B maybe electrically connected to form a vertical stacked-up configuration.In some alternative embodiments, a plurality of flexible structures(e.g., 100A and 100B) may be oriented parallel to and disposed over oneanother.

In some embodiments, the flexible structures 100A and 100B are bondedthrough a bonding layer 300. In some embodiments, the bonding layer 300is disposed between the coverlay layer 134A of the flexible structure100A and the coverlay layer 132B of the flexible structures 100B. Thebonding layer 300 may cover the lateral surface(s) 134AL/132BL and thetop surface(s) 134AT/132BT of the coverlay layer(s) 134A/132B and mayalso cover the surfaces of the first dielectric layers 110A and 110Bfacing towards each other. A material of the bonding layer 300 mayinclude polyimide (PI), polypropylene (PP), other suitable polymericmaterials, or suitable bonding materials. In some embodiments, the edgesof the bonding layer 300 may be vertically aligned to the respectiveedges EG of the circuit structure 200A. In some embodiments, the bondinglayer 300 is bonding the regions of the flexible structures 100A and100B where the circuit structure 200A is formed on, and a gap G may beformed between the flexible structures 100A and 100B at the region ofthe flexible structures 100A and 100B extending out from the edge EG ofthe circuit structure 200A. In some embodiments, the gap C1 is airgap.

In some embodiments, the conductive through hole(s) 111 may be laterallyencapsulated by the flexible structures 100A and 100B. The bonding layer300 may be in electrical and physical contact with the conductivepattern(s) 122A/124A/122B/124B of the flexible structures 100A and 100B.The conductive through hole(s) TH may pass through both of the flexiblestructures 100A and 100B to be in electrical and physical contact withthe first patterned conductive layer(s) 222A/224A′ of the circuitstructure 200A. That is, the conductive through hole(s) TH passingthrough the flexible structures 100A and 100B may provide electricalpaths between the circuit layers of the circuit structure 200A and theconductive patterns of the flexible structures 100A and 100B.

For example, after bonding the flexible structures 100A and 100B and theformation of the first pre-patterned dielectric layer(s) (e.g.,dielectric layer 2120, 2140 shown in FIG. 7) and the conductivematerial(s) (e.g., conductive material 2220, 2240 shown in FIG. 7),through hole(s) (not shown) may be formed at the predetermined positionsby, for example, mechanical or laser drilling, etching, or othersuitable removal techniques. Next, the through hole(s) may be platedwith conductive materials (e.g., copper) to a predetermined thickness,thereby providing the conductive through hole(s) TH. It should be notedthat the foregoing sequence merely serves as an illustrative example. Asreferred to herein, the conductive through hole(s) TH is not intended tobe limited to any particular type of electrically conductive material orany particular method of fabrication. The conductive through hole(s) THmay be solid or hollow, but not limited in the disclosure. In certainembodiments in which the conductive through hole(s) TH is hollow, aninsulating layer may be formed therein. The portion (e.g.,terminal-connecting portion Ct) of each flexible structure (e.g.,structure 100A, 100B) extending out from the edge EG of the circuitstructure 200A and stacked upon one another are oriented in the samedirection or may face toward different directions for externalelectrical connection. Accordingly, the integration of an electronicassembly may be improved and the insertion loss and/or return loss)causing by multi-connecting interfaces may be eliminated.

FIGS. 17 and 18 are schematic plan views showing different types ofcircuit carriers in accordance with some embodiments and FIG. 19 is aschematic view showing an application of a circuit carrier in accordancewith some embodiments. Referring to FIG. 17 and FIG. 18, a circuitstructure 200C of a circuit carrier C3 exhibits a rectangular shape witha top surface 200TS that may be parallel to a top surface 100TS of anextended portion EP of the flexible structure 1000. The flexiblestructure 100C may be similar to the above-mentioned flexible structure,for example, a portion of the flexible structure 100C is sandwichedwithin the circuit structure 200C and the other portion (i.e. theextended portion EP) of the flexible structure 100C extend out from thecircuit structure 200C. The extended portion EP may at least include theterminal-connecting portion Ct of the conductive pattern (e.g., 122)with the surface finish layer (e.g., 142) formed thereon. Since portionsof the conductive pattern (e.g., 122) are covered by the coverlay layer132, these portions of the conductive pattern (e.g., 122) areillustrated as dashed lines in the drawings. It should be appreciatedthat the layout of the top surface 200TS of the circuit structure 200Cand the top surface 100TS of the flexible structure 100C are omittedfrom the drawing for ease of description and any circuitry layout may beemployed as appropriate for a given application.

In some embodiments, panel-level processing is compatible with thecircuit carrier C3. For example, the circuit structure 200C and/or theflexible structure 100C of the circuit carrier C3 may be manufactured ina rectangular or polygonal shape or in accordance with the panel form.In some other embodiments, a large plurality of the circuit carriers C3are manufactured, which is cut into individual circuit carrier C3 whenthe manufacturing process is complete or nearly so. The cross-section ofthe circuit carrier C3 may be similar to that of the circuit carrier C1(or C2), so the detailed description is omitted for brevity.

As shown in FIG. 18, a circuit structure 200D of a circuit carrier C4may be formed to match the shape of the to-be-received electronicdevice, and the circuit structure 200D may be formed in a round orelliptical type (such as a wafer form). In some embodiments, the circuitcarrier C4 is compatible with the wafer level processing utilizing thewhole wafer or wafer form packages. The flexible structure 100Dsandwiched within the circuit carrier C4 includes the extended portionEP, functioning as a flexible connector or to provide a flexibleconnection. The cross-section of the circuit carrier C4 may be similarto that of the circuit carrier C1 (or C2), so the detailed descriptionis omitted for brevity.

Referring to FIG. 19, the circuit carrier C4′ may be similar to thecircuit carrier C4 except that the circuit carrier C4′ includes morethan one extended portions (e.g., portions EP1, EP2, EP3). In someembodiments, those extended portions EP1, EP2, EP3, extended from theedges of the circuit structure, are oriented in the different directionsdepending on the design requirements. Those extended portions EP1, EP2,EP3 may be configured in the same plane within the circuit structure. Inalternative embodiments, those extended portions EP1, EP2, EP3 may beinterposed in different stacked layers within the circuit structure. Inalternative embodiments, those extended portions may be verticallystacked over one another and may be oriented in the same direction.

The circuit carrier C4′ (or any one of the circuit carrier C1 throughC4) may be compatible with high-end device applications (e.g., highperformance computing application). For example, an electronic device400 is provided and may be mounted onto the circuit carrier C4′ directlyor may be mounted through any suitable electrical component (e.g.,interposer, package substrate, or the like) so as to form an electronicassembly. For example, the electronic device 400 may be a wafer formdevice or wafer form package including more than one chips 410 packagedtherein. The chips 410 may be arranged in an array in the wafer formpackage and may respectively be an application-specific integratedcircuit (ASIC) chip, an analog chip, a sensor chip, a wireless and radiofrequency chip, a voltage regulator chip, a memory chips, or anysuitable active or passive devices. The number of the chips 410 may beadjusted according to design of products, which is not limited in thedisclosure. In some embodiments, the chips 410 may be packaged using anysuitable semiconductor processes for protection.

In some embodiments, a wafer form electronic device 400 may be mountedonto the top surface 200TS of the circuit carrier C4′ through, forexample, conductive terminals (not shown). The circuit carrier C4′ maybe sized so as to be compatible with the wafer form electronic device400. In some embodiments, additional electronic device(s) (not shown)may be connected to the extended portion(s) EP1/EP2/EP3 of the circuitcarrier C4′ so as to provide electrical communication to (or between)the electronic device(s). Accordingly, it is not necessary to reservespace in the circuit carrier for the placement of connectors to installthe electronic device(s) so that the circuit carrier in the disclosureallows the size thereof to be effectively reduced, which in turn enablesthe installation space of the circuit carrier of the electronic assemblyto be desirably reduced so as to meet the demands of profileminiaturization of the electronic assembly.

FIG. 20 is a schematic cross-sectional view showing an electronicassembly, in accordance with some embodiments. Referring to FIG. 20, anelectronic assembly EA includes the circuit carrier C1, first electronicdevices 510, 520 disposed on a first side S1 of the circuit carrier C1,a second electronic device 530 disposed on the extended portion EP at asecond side S2 of the circuit carrier C1, and a plurality of externalterminals 540 disposed on a third side S3 of the circuit carrier C1. Thefirst side S1 and the third side S3 are opposite to each other and thesecond side S2 is connected to the first side S1 and the third side S3.It should be appreciated that the circuit carrier C2 through C4 or C4′described above may be applied to form the electronic assembly EA,according to some embodiments. The second electronic device 530 iselectrically and physically connected to the peripheral region 100P ofthe flexible structure 100. In some embodiments, the second electronicdevice 530 may be detachably connected to the flexible structure 100 ofthe circuit carrier C1. In some embodiments, the extended portion EP ofthe circuit carrier C1 serving as a plug-in connector is connected tothe second electronic device 530 in an electrically conductive manner.

In some embodiments, the first electronic devices 510 and 520 (or thesecond electronic device 530) may include semiconductor packages, suchas System-On-Chip (SoC), Chip-On-Wafer (CoW) packages,Integrated-Fan-Out (InFO) packages, Chip-On-Wafer-On-Substrate (CoWoS)packages, other three-dimensional integrated circuit (3DIC) packages,and/or the like. The first electronic device(s) 510, 520 and the secondelectronic device(s) 530 may include a wide variety of devices, such asprocessors, resistors, capacitors, transistors, diodes, fuse devices,memories, discrete electronic devices, power coupling devices or powersystems, thermal dissipation devices, and/or the like. The externalterminals 540 may be ball grid array (BGA) connectors, solder balls,metal pillars, and/or the like. In some embodiments, a high distributiondensity of the external terminals 540 is provided to meet the designrequirements. In some embodiments, the external terminals 540 areavailable to be mounted onto additional electrical component(s) (e.g.,circuit carrier(s), system board(s), mother board(s), etc.). Sinceelectronic devices may be directly mounted onto the circuit carrierwithout using additional connector(s), insertion loss and return lossdue to installation may be reduced, thereby improving the electricalperformance. Accordingly, good electrical match of the high speedinput/output to the electronic device(s) may be achieved, while themechanical reliability of the structure remains high.

In accordance with some embodiments of the disclosure, a circuit carrierfor coupling an electronic device includes a flexible structure and acircuit structure. The flexible structure includes a conductive patterndisposed on a surface of a first dielectric layer. The circuit structureincludes a second dielectric layer overlying the surface of the firstdielectric layer and a circuit layer disposed on the second dielectriclayer and connected to the conductive pattern. The flexible structure isembedded in and electrically connected to the circuit structure, and aportion of the flexible structure extends out from an edge of thecircuit structure to be plugged into the electronic device.

In accordance with some embodiments of the disclosure, a circuit carrierfor coupling an electronic device includes a first structure and asecond structure partially sandwiched in and electrically connected tothe first structure. The first structure includes a laminated dielectriclayer and a circuit layer disposed on the laminated dielectric layer. Aportion of the second structure extends out from an edge of the firststructure, the second structure includes a conductive pattern disposedon a surface of a flexible dielectric layer, where a portion of thelaminated dielectric layer of the first structure covers a lateralsurface of the conductive pattern of the second structure, and theportion of the laminated dielectric layer is in physical contact withthe surface of the flexible dielectric layer.

In accordance with some embodiments of the disclosure, a method ofmanufacturing a circuit carrier includes at least the following steps. Aconductive pattern is formed on a first dielectric layer to form aflexible structure. A second dielectric layer is formed on the firstdielectric layer of the flexible structure, where a Young's modulus ofthe second dielectric layer is greater than that of the first dielectriclayer. A patterned conductive layer is formed on the second dielectriclayer to be connected to the conductive pattern of the flexiblestructure. A peripheral portion of the patterned conductive layer isremoved to expose a peripheral portion of the conductive pattern of theflexible structure.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method of manufacturing a circuit carrier,comprising: forming a conductive pattern on a first dielectric layer toform a flexible structure; forming a second dielectric layer on thefirst dielectric layer of the flexible structure, wherein a Young'smodulus of the second dielectric layer is greater than that of the firstdielectric layer; forming a first patterned conductive layer on thesecond dielectric layer to be connected to the conductive pattern of theflexible structure; forming a third dielectric layer with a through holeon the first patterned conductive layer; forming a second patternedconductive layer on the third dielectric layer, wherein: a peripheralportion of the second patterned conductive layer extends across thethrough hole of the third dielectric layer to form a void enclosed bythe third dielectric layer, the peripheral portion of the secondpatterned conductive layer, and the peripheral portion of the firstpatterned conductive layer; and removing the peripheral portion of thesecond patterned conductive layer and the peripheral portion of thefirst patterned conductive layer to expose a peripheral portion of theconductive pattern of the flexible structure.
 2. The method of claim 1,wherein forming the flexible structure further comprises: forming acoverlay layer on the first dielectric layer to cover the conductivepattern, wherein the second dielectric layer is formed on the coverlaylayer of the flexible structure, and a portion of the first patternedconductive layer penetrates through the second dielectric layer and thecoverlay layer to be connected to the conductive pattern.
 3. The methodof claim 1, wherein forming the flexible structure further comprises:forming a surface finish layer on the peripheral portion of theconductive pattern.
 4. The method of claim 1, wherein forming the firstpatterned conductive layer on the second dielectric layer comprises:laminating a conductive material layer on the second dielectric layer;forming a sacrificial conductive pattern on the conductive materiallayer; removing a portion of the conductive material layer exposed bythe sacrificial conductive pattern; and removing the sacrificialconductive pattern after removing the peripheral portion of the firstpatterned conductive layer.
 5. The method of claim 4, wherein: afterlaminating the conductive material layer, an opening of the seconddielectric layer exposing the peripheral portion of the conductivepattern of the flexible structure is masked by the conductive materiallayer, and after removing the portion of the conductive material layerexposed by the sacrificial conductive pattern, the opening of the seconddielectric layer is unmasked.
 6. The method of claim 1, furthercomprising: after removing the peripheral portion of the first patternedconductive layer, forming a patterned mask layer on a remaining portionof the circuit layer, wherein the patterned mask layer partially exposesthe remaining portion of the circuit layer.
 7. A method of manufacturinga circuit carrier, comprising: forming a flexible structure comprising aconductive pattern formed on a first dielectric layer; forming a seconddielectric layer with a first through hole on the flexible structure;forming a first patterned conductive layer on the second dielectriclayer to be in contact with the conductive pattern of the flexiblestructure, wherein the first through hole of the second dielectric layeris covered by a non-circuitry portion of the first patterned conductivelayer; forming a third dielectric layer with a second through hole onthe second dielectric layer, wherein: the second through hole of thethird dielectric layer exposes the non-circuitry portion of the firstpatterned conductive layer, and the non-circuitry portion of the firstpatterned conductive layer separates the second through hole from thefirst through hole of the second dielectric layer; and removing thenon-circuitry portion of the first patterned conductive layer toaccessibly expose a non-circuitry portion of the conductive pattern ofthe flexible structure.
 8. The method of claim 7, wherein forming theflexible structure comprises: forming the conductive pattern on thefirst dielectric layer; and forming a coverlay layer on the conductivepattern, wherein the coverlay layer accessibly exposes the non-circuitryportion of the conductive pattern.
 9. The method of claim 7, furthercomprising: forming a surface finish layer on the non-circuitry portionof the conductive pattern before forming the second dielectric layer.10. The method of claim 7, wherein forming the second dielectric layerand forming the third dielectric layer comprise: performing a punchingprocess to respectively form the second dielectric layer with the firstthrough hole and the third dielectric layer with the second throughhole.
 11. The method of claim 7, wherein forming the first patternedconductive layer comprises: laminating a conductive material layer onthe second dielectric layer; and partially removing the conductivematerial layer in a circuitry portion to form the first patternedconductive layer.
 12. The method of claim 7, further comprising: forminga second patterned conductive layer on the third dielectric layer beforeremoving the non-circuitry portion of the first patterned conductivelayer, and forming the second patterned conductive layer comprising:laminating a conductive material layer on the third dielectric layer;and partially removing the conductive material layer to form the secondpatterned conductive layer.
 13. The method of claim 12, wherein: afterlaminating the conductive material layer, the second through hole of thethird dielectric layer is covered by a non-circuitry portion of theconductive material layer, and after partially removing the conductivematerial layer and before removing the non-circuitry portion of thefirst patterned conductive layer, the second through hole of the thirddielectric layer remains covered by the second patterned conductivelayer.
 14. A method of manufacturing a circuit carrier, comprising:forming a flexible structure comprising a conductive pattern formed on afirst dielectric layer; alternately forming a plurality of seconddielectric layers and a plurality of patterned conductive layers on theflexible structure, wherein each of the second dielectric layerscomprises a through hole above a peripheral portion of the flexiblestructure, and the through holes are isolated from one another byperipheral portions of the patterned conductive layers; and removing theperipheral portions of the patterned conductive layers to accessiblyexpose the peripheral portion of the flexible structure.
 15. The methodof claim 14, wherein forming the flexible structure comprises: formingthe conductive pattern on the first dielectric layer; and forming acoverlay layer on the conductive pattern, wherein the coverlay layeraccessibly exposes a peripheral portion of the conductive pattern. 16.The method of claim 14, further comprising: forming a surface finishlayer on a peripheral portion of the conductive pattern of the flexiblestructure before alternately forming the second dielectric layers andthe patterned conductive layers.
 17. The method of claim 14, whereinfurther comprising: performing a punching process to form the seconddielectric layers with the through holes before forming the seconddielectric layers on the flexible structure.
 18. The method of claim 14,wherein forming the patterned conductive layers comprises: laminating aconductive material layer on one of the second dielectric layers; andpatterning the conductive material layer.
 19. The method of claim 14,wherein removing the peripheral portions of the patterned conductivelayers comprises: after forming a topmost one of the patternedconductive layers, etching the peripheral portions of the patternedconductive layers that cover the through holes of the second dielectriclayers.
 20. The method of claim 14, further comprising: removing aredundant stack of the second dielectric layers and the patternedconductive layers after removing the peripheral portions of thepatterned conductive layers.